Aminopeptidase B (RNPEP)

Aminopeptidase B (EC 3.4.11.6) was originally defined as an exopeptidase capable of trimming basic amino acid residues from the NH2 terminus of peptide substrates (Hopsu et al., 1964).

Cadel et al. (1995) demonstrated that it is a Zn(2+)-dependent exopeptidase that selectively removes arginine and/or lysine residues from the N terminus of several peptide substrates. Structurally it is related to leukotriene A4 hydrolase, an important enzyme of the arachidonic acid pathway. The structural relationship has its functional counterpart in the capacity of aminopeptidase B to hydrolyze leukotriene A4 (Cadel et al., 1997). Antibodies raised against the isolated peptidase show that it is widely distributed in a number of tissues, including endocrine and nonendocrine cell types.